Speed trigger



Jan. 1, 1957 R. J. EMERSON SPEED TRIGGER 2 Sheets-Sheet l Filed Feb. 5, 1954 1l\"El\'TOR.

' all [maria ATTORNEYS a L i J n- 1957 R. J. EMERSON SPEED TRIGGER 2 Sheets-Sheet 2 Filed Feb. '5, 1954 V IAWENTOR. @wy Ma fmeiwaly ATTD RN EYS United StatesPaten't G SPEED TRIGGER Roy J. Emerson, Superior, Application February 5, 1954, Serial No. 408,496 2 1 Claim. (31. 42-49 "Ihis invention relates to an improved trigger assembly for military manually operated bolt action rifles, and in', particular a trigger assemblyin which a sear is pivotally mounted betweena finger lever and a striker stop whereby with the contacting surfaces of the sear and striker stop described on a radius, the center of which is positioned on the axis of a pin pivotally mounting the sear. in the firearm the release movement of the sear is performed Without lateral movement of the striker stop providing, a smooth even trigger pull and with the sear actuated by .the finger lever through a floating sear link positioned substantially close to the axis of the sear the semis adapted to travel at a much greater speed than if it were made an integral part of the finger lever.

The purpose of this invention is to provide an improved trigger assembly for bolt action rifles wherein the releasing action of the sear travels at a much greater speed than that ofthe sear of conventional rifles and wherein a more uniform pull is obtained on the finger lever so that the action is not influenced by the angle of pressure applied to the finger lever.

With a conventional trigger assembly of bolt action rifles where the sear is an integral part of the finger lever the releasing surface of the sear travels at the same speed as that of the finger lever and in numerous instances the releasing surface travels in a straight line resulting in frictional, contact with the. striker stop. With the parts assembled and mounted in this manner the angle of force applied to the trigger produces bindingbetween the parts unless the pull is in a plane perpendicular to a vertical plane through the axis of the finger lever. With this thought in mind this invention contemplates an improved trigger assembly for bolt action rifles wherein the finger lever is connected to the sear with a floating member whereby with the sear pivotally mounted the leverage between the point of contact with the floating element and striker stop may be increased to'step up .the action of the contacting surfaces .ofsthe sear and-striker stop whereby the trigger asembly functionswith high speed.

The .object of this invention is, therefore, to provide means for transmitting action from a finger lever of a trigger assembly to a strik er stop that'releases the firing pinvo .ho ,,thm an. in e e ate me n u has a sear, in which the leverage is increased in the sear to increase the speed of the releasing surface of the sear with the striker stop.

Another object of the invention is to provide an improved trigger assembly for bolt action rifles in which the contacting surface of a pivotally mounted sear with a striker stop is described on a radius, the center of which is positioned on the axis of the pivotal mounting element of the sear whereby the contacting surface of the sear leaves the striker stop with a smooth even action.

A further object of the invention is to provide an improved trigger assembly for bolt action rifles in which the sear is independently mounted in the firearm and connected to a finger lever with a sear link that provides a floating element.

A still further object of the invention is to provide an improved trigger assembly for bolt action rifles that provides a high speed releasing action and in which a sear is pivotally mounted independent of a finger lever in which the assembly is of a comparatively simple and economical construction.

With these and other objects and advantages in view the invention embodies a trigger assembly for a bolt action rifle in which a finger lever pivotally mounted in a recess through a stock of a rifle is freely connected to a sear also pivotally mounted in the recss with a sear link and the sear is provided with an arcuate surface described on a radius from the axis of the pivotal mounting thereof which engages the striker stop that holds the bolt in the cocked position, in which a spring is provided for returning the sear and striker stop and also in which a set screw is provided for adjusting the position of the finger lever.

Other features and advantages of the invention will appear from the following description taken in connection with the drawings, wherein:

Figure 1 is a longitudinal section through the stock of a firearm showing the relative positions of a finger lever, sear, and striker stop with the parts in their respective positions before firing.

Figure 2 is a view similar to that shown in Fig. 1 showing the positions of the parts after firing the rifle.

Figure 3 is a view showing the trigger framework of the assembly.

Figure 4 is a detail showing the sear link for freely connecting the finger lever to the sear.

Figure 5 is a detail showing a pin adapted to be mounted in the striker stop for providing a spring guide.

Figure 6 is a detail showing a block adapted to be mounted in the trigger framework and in which an adjusting screw for regulating the action of the finger lever is positioned.

Figure 7 is a detail illustrating the striker stop of the assembly.

Figure 8 is a similar view showing the finger lever.

Figure 9 shows the sear.

Figure 10 shows a spring positioned between the sear and striker stop.

Referring now to the drawings wherein like reference characters denote corresponding parts the improved trigger assembly of this invention includes a trigger 10, a sear latch 11, a sear 12, a trigger framework including side plates 13 and 14, a block 15 positioned between the side plates and adapted to provide a mounting for an adjusting screw 16, a spring 17 and a guide pin 18 which is mounted in the sear 12 and which provides a guide for the spring.

As illustrated in the drawings the trigger 10 is pivotally mounted inthe trigger framework on a pin. 19 and the trigger is positioned whereby a finger grip 20 extends intoa guard 21 on the lower surface of the stock 22. The upper part of the trigger is provided with a projection or lip 23 that is positioned to engage the adjusting screw 16 and the upper end 24 of the trigger is positioned to prevent small foreign particles of dirt from falling between contact surface of projection 23 and adjusting screw 16.

The upper part of the trigger 10 is also provided with an arcuate surface 27 against which a surface 28 on the upper end of the sear latch 11 rides, as illustrated in Fig. 2, and the lower part of the trigger is provided with a notch 29 into which the smaller end of the trigger link or connecting member 30 extends with the parts assembled, as shown in Figs. 1 and 2. The opposite end of the trigger link is provided with an enlarged cylindrical element 31 that is positioned in a recess 32 in the lower part of the sear latch and with the sear latch pivotally mounted by .a pin 33 in an opening 34 it will be noted that. the distance from the axis of the pin 33 to the arcuate surface 35 on the upper end-of'the sear latch is greater than the distance betweenthe axis of the pin 33 and recess 32. With the sear latch formed in this manner the upper surface 35 of the sear travels at a greater speed than the socket 32' in which the part 31 of the trigger link is positioned.

The upper surface 35 of the sear latch is described on a radius the center of which is positioned on the axis of the pin 33 whereby the sear latch slides against the under surface of the sear 12 with a smooth easy movement.

The sear 12 is pivotally mounted by a pin 36 that extends through an opening 37 therein in the trigger framework and the lower side of the sear is provided with a socket 38 in which a head 39 on the upper end of the spring guide pin 18 is positioned and, as illustrated in Figs. 1 and 2 the lower end of the pin 18 extends through an opening 40 in a finger or projection 41 extended from the sear latch 11.' The spring 17 through which the pin 18 extends is positioned between the projecton 41 and the lower surface of the sear 12.

The block 15 is secured between the side plates of the trigger framework with pins 42 and 43 and the adjusting screw 16 is threaded in a projection 44 extended from one end of the block 15. The pins 42 and 43 extend through openings 45 and 46 in the block 15 and also through openings 47 and 48, respectively in the side plates 13 and 14 of the trigger framework. The side plates are also provided with aligned openings 49 in which the ends of the pin 36 are positioned, similarly positioned openings 50 in which the ends of the pin 19 are positioned and similarly positioned openings 51 in which the ends of the pin 33 are positioned. The openings 50 and 51 are located in depending sections 52 of the side plates. The trigger 10 is also provided with an opening 53 that is aligned with the openings 50 and in which the pin 19 is located. The side plates 13 and 14 are also provided with openings 54 for connecting the trigger framework to the rifle receiver, and these openings are aligned with an opening 55 in the block 15.

With the parts assembled in a stock, such as the stock 22 of a rifie as illustrated in Figs. 1 and 2 pressure applied to the finger grip 20 is transmitted to the lower end ofthe sear latch 11 by the floating trigger link 30 with the result that the arcuate surface 35 on the 4 upper end of the sear latch slides away from the lower surface of the sear 12 permitting a tooth 56 extended from the bolt 57 to force the sear 12 downwardly thereby releasing the bolt and firing pin of the rifle. The bolt tooth 56 rides forward on the sear extension 25, holding the bolt stop 12 in its down position as in Figure 2. The spring 17, being held in place by the spring guide 18 supplies the required trigger pull weight or load which is approximately three pounds, and also provides means for returning the parts to the firing position when the bolt 57 is operated for the next shot. With the sear latch mounted independently of the trigger the move- 4 ment of the sear latch is pressure applied to the trigger and the trigger backlash is substantially eliminated.

With the projection 23 of the trigger 10 in engagement with the adjusting screw 16 the parts may readily be adjusted to provide a short light pull or a long heavy pull on the trigger.

It will be understood that'mo'difications, within the scope of the appended claims, may be made in the design and arrangement of the parts without departing from the spirit of the inventione What is claimed is:

In a trigger assembly for a firearm, a pair of spaced side plates providing a trigger framework, a block positioned between said pair of side plates, an adjusting screw connected to said block, a trigger pivotally mounted in said framework and having an arcuate finger grip extended from its lower end, a lip extending from the upper portion of said trigger and engaging said adjusting screw, the upper end ofsaid trigger preventing small foreign particles from falling between the contact surface of said lip and the adjusting screw, a sear pivotally' mounted in the framework and positioned to engage a projection of a bolt of a firing pin of 'the firearm, a seat latch also pivotally mounted in said framework and positioned between the trigger and'sear with an arcuate.

surface on the extended end furthest from the pivotal mounting of the sear latch and positioned to engage the under surface of the sear, the upper part of said trigger being provided with an arcuate surface against which a surface onthe upper end of the sear latchirides, a floating trigger link positioned with one end extended into a notch in the trigger and the other into a recess of the sear latch, the distance between the recess in the sear latch and the pivotal mounting thereof being less than the distance from the pivotal mounting to the arcuate surface at the end of the sear latch so that the upper surface of the sear latch travels at a greater speed than the recess in which the end of the trigger link is positioned, a finger extending from said sear latch and provided with an opening therein, a guide pin connected to said sear and extending through the opening in said finger, a spring between the sear latch and sear and. said spring being c'ircurnposed on said guide pin and positioned to return the parts to holding position with the firearm cocked upon return of the firing pin actuating bolt, the center of the radius of the arcuate surface of the sear latch being positioned on the pivotal axis of' the sear latch whereby 'the sear latch slides against the under surface of the sear with a smooth easy movement".

References Cited in the file of this patent UNITED STATES PATENTS not affected by the angle of 

